Increasing IP range

[taonga]

I need o increase the ip range of a network to accommodate more ip addresses. The current ip range is 172.21.2.1 255.255.255.0, Iknow that i can change the subnet to 255.255.254.0 which will give more addresses, but there servers and routers with the 255.255.255.0 subnet that i would like to use without changing anything on them.
How can i go about this

 

[syntax]

If you want a bigger range, then you need to change the subnet everywhere to match that range.
If you want a new range, you will need to have this range available on your routers and add routing for this

 

[ponder]

Do you have any subnets on either side of 172.21.2.0?

Actually just give us a list on network ranges you use and we'll advise accordingly.

 

[MDKza]

Like what was said here. If you change the subnet mask you will have to change it everywhere if the devices are on the same.
If you have a router or a layer 3 switch to route the traffic you can just add another VLAN.

 

[srothman]

Sort out the router configuration to actually do it's job and route. You shouldn't have your network kit, servers, workstations, printers, etc. all on the same VLAN, it's a poor design.

Create separate VLANs for your business services, e.g.

Servers
172.21.2.x / 255.255.255.0

Workstations
172.21.3.x / 255.255.255.0

Switches
172.21.4.x / 255.255.255.0

Printers
172.12.5.x / 255.255.255.0